Condensing boilers

Condensing boilers

System Description

As one of the first brands that developed technologies aimed at energy saving and environmentally friendly technologies such as the technology using condensation, Geminox quite naturally pays attention to technologies that use renewable energy sources. Currently, the Geminox brand is still actively trying to develop a complete range of solutions connecting high performance, energy saving and environmental awareness. Geminox condensing boilers provide everyday comfort while preserving the environment for future generations.

Geminox condensing boilers:

      • devices with optimum performance and technology that enables significant reduction in energy consumption compared to conventional boilers or the use of natural renewable energy sources;
    • the concept based on durable and recyclable materials such as stainless steel in which Geminox is a real expert. This material is easily sorted and recycled and it supports sustainable development;
    • production process which integrates a maximum considerate approach to the environment, e.g. the painting line in a factory is designed so that the negative impact on the environment is maximally reduced.

The third stage is adaptable equithermal regulation integrated in Siemens LMS boiler control unit which prevents unnecessary exposure of walls of the building to cold and optimizes thermal comfort in the building and increases the efficiency of the entire heating system. The above-standard saving is offered by condensing boilers by connecting solar collectors. LMS control unit is ready for easy extension of the heating system and by other alternative sources.


The fourth stage is the intelligent speed control of a low-energy circulating pump of Class A. This feature significantly reduces the return water temperature during transition periods and thereby dramatically expands the zone of the use of condensation. Also the overall reduction in energy consumption is not insignificant.

The fifth, the most important stage is represented by a wide linear modulation allowing uniform heating of the building without unnecessary cycling of the boiler. It is no secret that during ¾ of the heating season 15-50% of rated output of the boiler is dully sufficient. All conventional boilers, at which it is not possible to reduce the power to these values ​​while preserving the guaranteed efficiency, thus become significantly uneconomic for ¾ of the heating season. One of the most powerful advantage of THRs boilers is the ability to work with the maximum efficiency and without cycling even at the most common outdoor temperatures in the range of 5-15 ˚C. This advantage is mostly demonstrated in modern family houses. Today's new buildings usually have a heat loss around 10 kW. According to the above stated, practically-tested principles it is therefore necessary for the normal operation of such a building to reach the starting power of the boiler lower than 3 kW. If this parameter is not satisfied and the boiler is operated outside its operating range, the so-called cycling begins. Standard boilers with the starting power of 6-8 kW undergo such switching off and on up to 40,000 times per year. This number seems very untrustworthy but after a conversion to heating days in a year it means one start of the boiler every 10 minutes. However, we know from our experience that even minute intervals are no exception. The properly selected Geminox THRs condensing boiler will not make more than 4,000 starts per year in a newly constructed building It must be clear even to an amateur what conclusion can be drawn from these data.

Geminox THRS condensing boilers are, by their parameters, among the most economical devices on the market.

  • Minimum performance greatly affects operation economy (reduction in the number of cycles). Maximum performance provides the comfort of heating and hot water production.
  • If we consider a simple heating system (radiators or floor heating), the appropriate solution is the GROUND condensing boiler with a basic regulation.
  • In the case of a combined heating system (radiators + floor heating), the optimal solution is the THRs condensing boiler in the DC design with a basic regulation.
  • For more complicated systems with a second source of heat (e.g. heat-conducting fireplace) or more heating circuits, the suitable solution is the THRs condensing boiler in the C design with an appropriate regulation of Albatros RVS series..
  • For one-family housing, the usual container volumes are from 48 to 75 litres for one bathroom or a shower and 120 litres for two bathrooms.
  • For a duplex housing with one bathroom per apartment, the container volume of at least 150 litres is desirable.
  • In the case of the above-standard container volume, the required minimum container volume is of at least 50% of the bathtub volume.
  • If the hot water is heated in the solar tank, it is necessary to double the minimum container volume.

Consult the professionals on which condensing boiler is the best for you.

kondenzačný kotol THRs


They are prepared well even for the most demanding applications. Already the fourth generation of condensing boilers labelled THRs (Trés Haut Rendement - very high efficiency) with the Siemens LMS control unit is intended wherever the achievement of an ideal thermal comfort with minimum operating costs is a clear priority. High quality design elements of boilers, such as the patented stainless steel burner, large stainless steel heat exchanger or stainless steel hot water container, are complemented with the state-of-the-art Siemens LMS control unit. In addition to the standard combustion and security features, it also controls several heating circuits including hot water production. The basic equipment of the automation includes the functions of solar heating, possible combination with alternative sources or cascades control. THRs condensing boilers are available in these versions:

  • THRS C - solo single-circuit condensing boiler (only for heating with the possibility to connect an external HW tank)
  • THRs M 75 H - condensing boiler with an integral indirect-heating stainless steel tank with a volume of 75 litres (horizontal version)
  • THRs M 75 V - condensing boiler with an integral indirect-heating stainless steel tank with a volume of 75 litres (vertical version)
  • THRs B 120 - condensing boiler with an integral indirect-heating stainless steel tank with a volume of 120 litres (stationary version)

Rez kotlom Geminox THRs DC


THRs DC version also allows:

  • heating of a direct heating circuit (usually radiators)
  • heating of a mixed heating circuit (usually floor heating)
  • hot water production for 1-2 bathrooms with circulation possibility
  • solar system of hot water production
  • possibility of swimming pool heating

THRs DC condensing boiler is specifically optimized for the use in modern houses and is available in the following versions:

  • THRs DC condensing boiler  - wall design as a separate boiler prepared for example to be a part of a set with a solar tank
  • THRs M 75 H DC condensing boiler - wall design with an integrated 75l tank
  • THRs B 120 DC condensing boiler - stationary design with an integrated 120l  tank
  • THRs SET DC condensing boiler - a combination with an external enamel or stainless steel HW tank

THRs DC condensing boiler is fully equipped with all necessary hydraulic and regulatory elements including cabling. It has an identical size with its standard variant designed for conventional single-circuit heating and it is therefore very compact. This solution offers many advantages such as elegant appearance, small size, fast installation, elimination of any installation errors. It also prevents inappropriate use of hydraulic elements such as favourite mixing manifolds for the floor heating circuit controlled by a thermostatic head. Because of its construction, these manifolds are not able to fulfil their function in combination with high-quality condensing boilers.

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